1. Field of the Invention
This invention relates to a method and apparatus for flaring or burning gas, and more particularly, to a method and apparatus which safely and efficiently flares or burns gas from an oil well.
2. Description of the Related Art
When oil is extracted from the earth, a certain amount of gas comes up through the well. In situations where there is no convenient way to collect the gas, it is simply burned. Several devices have been developed to flare or burn the gas.
In normal operation of an oil well, a mixture of oil, gas and water or other liquid comes up through a pipe under varying degrees of pressure. When the mixture reaches the surface it is fed into a three-stage vessel which separates the gas and water from the oil. The gas normally is sent through a vertical pipe extending above the ground and burned. The water and other liquids are deposited into a pit adjacent to the well. That pit often contains flammable material. Burning the gases directly into the atmosphere sometimes can result in the flammable materials in the pit catching on fire.
Systems for flaring or burning gas from oil wells are known in the art. Conventional methods for flaring or burning gas include methods wherein a flow of gas is directed into an expansion chamber where expansion and condensation take place. The gas is then transmitted upwardly within the chamber where it is vented and burned as it exits from the open top of the chamber. Quinnell, U.S. Pat. No. 4,610,622 teaches a method and apparatus for igniting flare gas using the above-mentioned technique. Quinnell includes an aperture provided for allowing condensation in any other vapors or fluids to drain into the bottom portion of the chamber, where they are drained away. Cullinane, Jr., U.S. Pat. No. 3,662,669, teaches an airflow control for a flare stack. Cullinane teaches a housing, divided into a series of interconnected longitudinally extending annular passages, through which gases rising in the stack flow upwardly and downwardly and again upwardly, creating zones at different pressures in the housing to limit the volume of air flowing downwardly into the stack when an upward flow of gas is interrupted. Cullinane includes a "gooseneck" pipe for draining condensation, rain, snow, etc. from the stack without venting gas through the gooseneck. Frost et al., U.S. Pat. No. 2,971,605, discloses, in a method and apparatus for flaring combustible gaseous materials, the hydrostatic regulation of gas pressure, i.e., a reservoir of water is utilized to impede the flow of gas into a combustion area until the gas is of a sufficient pressure.